<p>This study aimed to explore two main research objectives. The first objective focused on the extent to which English and Mathematics teachers integrate four key 21^st century skills (i.e., creativity, collaboration, critical thinking, and communication) into their teaching practices. The second objective was to identify the major barriers that prevent English and Mathematics teachers from effectively incorporating these 21^st century skills into their teaching practices. To address these objectives, a sequential exploratory mixed-method research design was employed. In the first phase, observations were conducted with 20 English and 20 Mathematics teachers to assess the extent of their integration of these skills. Following the observations, semi-structured interviews were conducted with 10 English and 10 Mathematics teachers to gather more detailed information about the major barriers that prevent the integration of the four primary 21^st century skills into their teaching practices. In the second, quantitative phase, the insights gained from the interviews were used to develop a questionnaire, which was completed by 89 Mathematics and 84 English teachers. The questionnaire aimed to validate the key obstacles that hinder English and Mathematics teachers from incorporating these skills into their instruction. The findings indicated that both English and Mathematics teachers incorporated creativity, critical thinking, collaboration, and communication skills at a very weak level. The results also showed that major obstacles, including barriers related to students, teachers, curriculum, and administration, impeded the integration of the four 21^st century skills into the teaching practices of English and Mathematics teachers. Overall, the findings obtained have important implications for future research and educational practices.</p>